In recent years, there has been developed a hybrid vehicle that combines an internal combustion engine and a motor generator (hereinafter referred to simply as “motor”) as power sources. As one form of a drive device for use in such a hybrid vehicle, there are proposed drive devices of a parallel type configured by simple replacement, in which a rotary electric machine (motor generator) drivably coupled to an input shaft of a speed change mechanism and an engine connection clutch (starting clutch) that connects and disconnects (engages and disengages) an engine coupling shaft drivably coupled to the internal combustion engine and the input shaft of the speed change mechanism are disposed in a portion for a starting device (such as a torque converter, for example) of a general automatic transmission.
Among such drive devices, there is proposed a drive device configured to include two power transfer paths, namely a power transfer path through which rotation of a motor is transferred to an oil pump and a power transfer path through which rotation of an engine is transferred to the oil pump, in which a one-way clutch is provided in each of the power transfer paths so that rotation of at least one of the motor and the engine is transferred to the oil pump (see Patent Document 1). In the drive device, the power transfer path from the motor to the input shaft of the speed change mechanism couples a clutch drum coupled to a rotor of the motor and splined to outer friction plates of the starting clutch and the input shaft of the speed change mechanism (and also wheels). Therefore, a flange-like carrier and a damper are interposed between the clutch drum and the input shaft so that the rotor and the input shaft are rotatable together with each other. Consequently, it is necessary for the power transfer path from the engine to the oil pump to extend across the power transfer path from the motor to the input shaft. Thus, a stepped planetary gear, which is a part of the power transfer path from the engine to the oil pump, is rotatably provided to penetrate the carrier.